2 * Copyright (c) 2013 Google, Inc
5 * Pavel Herrmann <morpheus.ibis@gmail.com>
6 * Marek Vasut <marex@denx.de>
8 * SPDX-License-Identifier: GPL-2.0+
14 #include <dm/uclass-id.h>
16 #include <linker_lists.h>
17 #include <linux/list.h>
21 /* Driver is active (probed). Cleared when it is removed */
22 #define DM_FLAG_ACTIVATED (1 << 0)
24 /* DM is responsible for allocating and freeing platdata */
25 #define DM_FLAG_ALLOC_PDATA (1 << 1)
27 /* DM should init this device prior to relocation */
28 #define DM_FLAG_PRE_RELOC (1 << 2)
30 /* DM is responsible for allocating and freeing parent_platdata */
31 #define DM_FLAG_ALLOC_PARENT_PDATA (1 << 3)
33 /* Allocate driver private data on a DMA boundary */
34 #define DM_FLAG_ALLOC_PRIV_DMA (1 << 4)
37 * struct udevice - An instance of a driver
39 * This holds information about a device, which is a driver bound to a
40 * particular port or peripheral (essentially a driver instance).
42 * A device will come into existence through a 'bind' call, either due to
43 * a U_BOOT_DEVICE() macro (in which case platdata is non-NULL) or a node
44 * in the device tree (in which case of_offset is >= 0). In the latter case
45 * we translate the device tree information into platdata in a function
46 * implemented by the driver ofdata_to_platdata method (called just before the
47 * probe method if the device has a device tree node.
49 * All three of platdata, priv and uclass_priv can be allocated by the
50 * driver, or you can use the auto_alloc_size members of struct driver and
51 * struct uclass_driver to have driver model do this automatically.
53 * @driver: The driver used by this device
54 * @name: Name of device, typically the FDT node name
55 * @platdata: Configuration data for this device
56 * @parent_platdata: The parent bus's configuration data for this device
57 * @of_offset: Device tree node offset for this device (- for none)
58 * @of_id: Pointer to the udevice_id structure which created the device
59 * @parent: Parent of this device, or NULL for the top level device
60 * @priv: Private data for this device
61 * @uclass: Pointer to uclass for this device
62 * @uclass_priv: The uclass's private data for this device
63 * @parent_priv: The parent's private data for this device
64 * @uclass_node: Used by uclass to link its devices
65 * @child_head: List of children of this device
66 * @sibling_node: Next device in list of all devices
67 * @flags: Flags for this device DM_FLAG_...
68 * @req_seq: Requested sequence number for this device (-1 = any)
69 * @seq: Allocated sequence number for this device (-1 = none). This is set up
70 * when the device is probed and will be unique within the device's uclass.
73 const struct driver *driver;
76 void *parent_platdata;
78 const struct udevice_id *of_id;
79 struct udevice *parent;
81 struct uclass *uclass;
84 struct list_head uclass_node;
85 struct list_head child_head;
86 struct list_head sibling_node;
92 /* Maximum sequence number supported */
93 #define DM_MAX_SEQ 999
95 /* Returns the operations for a device */
96 #define device_get_ops(dev) (dev->driver->ops)
98 /* Returns non-zero if the device is active (probed and not removed) */
99 #define device_active(dev) ((dev)->flags & DM_FLAG_ACTIVATED)
102 * struct udevice_id - Lists the compatible strings supported by a driver
103 * @compatible: Compatible string
104 * @data: Data for this compatible string
107 const char *compatible;
111 #ifdef CONFIG_OF_CONTROL
112 #define of_match_ptr(_ptr) (_ptr)
114 #define of_match_ptr(_ptr) NULL
115 #endif /* CONFIG_OF_CONTROL */
118 * struct driver - A driver for a feature or peripheral
120 * This holds methods for setting up a new device, and also removing it.
121 * The device needs information to set itself up - this is provided either
122 * by platdata or a device tree node (which we find by looking up
123 * matching compatible strings with of_match).
125 * Drivers all belong to a uclass, representing a class of devices of the
126 * same type. Common elements of the drivers can be implemented in the uclass,
127 * or the uclass can provide a consistent interface to the drivers within
131 * @id: Identiies the uclass we belong to
132 * @of_match: List of compatible strings to match, and any identifying data
134 * @bind: Called to bind a device to its driver
135 * @probe: Called to probe a device, i.e. activate it
136 * @remove: Called to remove a device, i.e. de-activate it
137 * @unbind: Called to unbind a device from its driver
138 * @ofdata_to_platdata: Called before probe to decode device tree data
139 * @child_post_bind: Called after a new child has been bound
140 * @child_pre_probe: Called before a child device is probed. The device has
141 * memory allocated but it has not yet been probed.
142 * @child_post_remove: Called after a child device is removed. The device
143 * has memory allocated but its device_remove() method has been called.
144 * @priv_auto_alloc_size: If non-zero this is the size of the private data
145 * to be allocated in the device's ->priv pointer. If zero, then the driver
146 * is responsible for allocating any data required.
147 * @platdata_auto_alloc_size: If non-zero this is the size of the
148 * platform data to be allocated in the device's ->platdata pointer.
149 * This is typically only useful for device-tree-aware drivers (those with
150 * an of_match), since drivers which use platdata will have the data
151 * provided in the U_BOOT_DEVICE() instantiation.
152 * @per_child_auto_alloc_size: Each device can hold private data owned by
153 * its parent. If required this will be automatically allocated if this
155 * TODO(sjg@chromium.org): I'm considering dropping this, and just having
156 * device_probe_child() pass it in. So far the use case for allocating it
157 * is SPI, but I found that unsatisfactory. Since it is here I will leave it
158 * until things are clearer.
159 * @per_child_platdata_auto_alloc_size: A bus likes to store information about
160 * its children. If non-zero this is the size of this data, to be allocated
161 * in the child's parent_platdata pointer.
162 * @ops: Driver-specific operations. This is typically a list of function
163 * pointers defined by the driver, to implement driver functions required by
165 * @flags: driver flags - see DM_FLAGS_...
170 const struct udevice_id *of_match;
171 int (*bind)(struct udevice *dev);
172 int (*probe)(struct udevice *dev);
173 int (*remove)(struct udevice *dev);
174 int (*unbind)(struct udevice *dev);
175 int (*ofdata_to_platdata)(struct udevice *dev);
176 int (*child_post_bind)(struct udevice *dev);
177 int (*child_pre_probe)(struct udevice *dev);
178 int (*child_post_remove)(struct udevice *dev);
179 int priv_auto_alloc_size;
180 int platdata_auto_alloc_size;
181 int per_child_auto_alloc_size;
182 int per_child_platdata_auto_alloc_size;
183 const void *ops; /* driver-specific operations */
187 /* Declare a new U-Boot driver */
188 #define U_BOOT_DRIVER(__name) \
189 ll_entry_declare(struct driver, __name, driver)
192 * dev_get_platdata() - Get the platform data for a device
194 * This checks that dev is not NULL, but no other checks for now
196 * @dev Device to check
197 * @return platform data, or NULL if none
199 void *dev_get_platdata(struct udevice *dev);
202 * dev_get_parent_platdata() - Get the parent platform data for a device
204 * This checks that dev is not NULL, but no other checks for now
206 * @dev Device to check
207 * @return parent's platform data, or NULL if none
209 void *dev_get_parent_platdata(struct udevice *dev);
212 * dev_get_parentdata() - Get the parent data for a device
214 * The parent data is data stored in the device but owned by the parent.
215 * For example, a USB device may have parent data which contains information
216 * about how to talk to the device over USB.
218 * This checks that dev is not NULL, but no other checks for now
220 * @dev Device to check
221 * @return parent data, or NULL if none
223 void *dev_get_parentdata(struct udevice *dev);
226 * dev_get_priv() - Get the private data for a device
228 * This checks that dev is not NULL, but no other checks for now
230 * @dev Device to check
231 * @return private data, or NULL if none
233 void *dev_get_priv(struct udevice *dev);
236 * struct dev_get_parent() - Get the parent of a device
238 * @child: Child to check
239 * @return parent of child, or NULL if this is the root device
241 struct udevice *dev_get_parent(struct udevice *child);
244 * dev_get_uclass_priv() - Get the private uclass data for a device
246 * This checks that dev is not NULL, but no other checks for now
248 * @dev Device to check
249 * @return private uclass data for this device, or NULL if none
251 void *dev_get_uclass_priv(struct udevice *dev);
254 * dev_get_of_data() - get the device tree data used to bind a device
256 * When a device is bound using a device tree node, it matches a
257 * particular compatible string as in struct udevice_id. This function
258 * returns the associated data value for that compatible string
260 ulong dev_get_of_data(struct udevice *dev);
263 * device_get_uclass_id() - return the uclass ID of a device
265 * @dev: Device to check
266 * @return uclass ID for the device
268 enum uclass_id device_get_uclass_id(struct udevice *dev);
271 * device_get_child() - Get the child of a device by index
273 * Returns the numbered child, 0 being the first. This does not use
274 * sequence numbers, only the natural order.
276 * @dev: Parent device to check
277 * @index: Child index
278 * @devp: Returns pointer to device
280 int device_get_child(struct udevice *parent, int index, struct udevice **devp);
283 * device_find_child_by_seq() - Find a child device based on a sequence
285 * This searches for a device with the given seq or req_seq.
287 * For seq, if an active device has this sequence it will be returned.
288 * If there is no such device then this will return -ENODEV.
290 * For req_seq, if a device (whether activated or not) has this req_seq
291 * value, that device will be returned. This is a strong indication that
292 * the device will receive that sequence when activated.
294 * @parent: Parent device
295 * @seq_or_req_seq: Sequence number to find (0=first)
296 * @find_req_seq: true to find req_seq, false to find seq
297 * @devp: Returns pointer to device (there is only one per for each seq).
298 * Set to NULL if none is found
299 * @return 0 if OK, -ve on error
301 int device_find_child_by_seq(struct udevice *parent, int seq_or_req_seq,
302 bool find_req_seq, struct udevice **devp);
305 * device_get_child_by_seq() - Get a child device based on a sequence
307 * If an active device has this sequence it will be returned. If there is no
308 * such device then this will check for a device that is requesting this
311 * The device is probed to activate it ready for use.
313 * @parent: Parent device
314 * @seq: Sequence number to find (0=first)
315 * @devp: Returns pointer to device (there is only one per for each seq)
316 * Set to NULL if none is found
317 * @return 0 if OK, -ve on error
319 int device_get_child_by_seq(struct udevice *parent, int seq,
320 struct udevice **devp);
323 * device_find_child_by_of_offset() - Find a child device based on FDT offset
325 * Locates a child device by its device tree offset.
327 * @parent: Parent device
328 * @of_offset: Device tree offset to find
329 * @devp: Returns pointer to device if found, otherwise this is set to NULL
330 * @return 0 if OK, -ve on error
332 int device_find_child_by_of_offset(struct udevice *parent, int of_offset,
333 struct udevice **devp);
336 * device_get_child_by_of_offset() - Get a child device based on FDT offset
338 * Locates a child device by its device tree offset.
340 * The device is probed to activate it ready for use.
342 * @parent: Parent device
343 * @of_offset: Device tree offset to find
344 * @devp: Returns pointer to device if found, otherwise this is set to NULL
345 * @return 0 if OK, -ve on error
347 int device_get_child_by_of_offset(struct udevice *parent, int seq,
348 struct udevice **devp);
351 * device_find_first_child() - Find the first child of a device
353 * @parent: Parent device to search
354 * @devp: Returns first child device, or NULL if none
357 int device_find_first_child(struct udevice *parent, struct udevice **devp);
360 * device_find_first_child() - Find the first child of a device
362 * @devp: Pointer to previous child device on entry. Returns pointer to next
363 * child device, or NULL if none
366 int device_find_next_child(struct udevice **devp);
369 * dev_get_addr() - Get the reg property of a device
371 * @dev: Pointer to a device
375 fdt_addr_t dev_get_addr(struct udevice *dev);